Render textured mesh of multiple materials without light
There are various ways of getting control over your shadow.  Shadows, ambient occlusion, and contrast can be controlled by nodes in the compositing window to to get the look you want.
I think that turning off the shadows cast by lights falling on the objects in your room, and turning on the ambient occlusion on these materials may help.
I am not sure exactly what nodes in the compositing editor you should add in order to control the shadows in the way you want, typical choices are mix nodes, or color ramps.